2 layers116 × 40 mm
2 layers116 × 40 mm
Briefkastensensor
hierle/letterbox-sensor17LoRaWan letterbox sensor
- Size
- 116 × 40 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 14
- Nets
- 23
- Pads
- 57
- Tracks, vias
- 151, 85
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 10 Oct 2019
- Updated
- 18 Jan 2024
Overview
Briefkastensensor is an open-source printed circuit board by hierle, from the hierle/letterbox-sensor repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 116 × 40 mm with 14 parts on 23 nets, routed with 151 tracks and 85 vias.
It is built around the ATTINY84-20PU, HSDL-9100-021 and RFM95W. Its parts include 3 resistors, 2 diodes, 1 capacitor, 1 IC and 1 inductor. It belongs with the sensors and measurement boards and the AVR (ATmega, ATtiny) boards of this library.
Main components
3
ATTINY84-20PU
PDIP-14-40℃~+85℃ 10bit 12 2.7V~5.5V 20MHz 512Byte 512Byte 8 Bit 8KB AVR Built-in FLASH PDIP-14 Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
HSDL-9100-021
SMD-4P-40℃~+85℃ 0mm~60mm Crosstalk cancellation Infrared SMD-4P Proximity Sensors ROHSBroadcom LimitedProximity SensorsRFM95W
SMD-16PUncategorisedHopeRF Micro-electronics
README
README.mdLoRaWan EU868MHz Letterbox Sensor
New version letterbox sensor v2 available here: https://github.com/hierle/letterbox-sensor-v2 :)
sensing letters in your letterbox via IR diode pair, sending out status via LoRaWan/TTN based on Attiny84, RFM95W, HSDL9100, powered by a CR2032 battery.
This is basically a clone of the heise ct briefkasten sensor project
https://www.heise.de/ratgeber/IoT-Netz-LoRaWAN-Briefkastensensor-mit-hoher-Reichweite-selber-bauen-4417179.html
https://github.com/jamct/radio-mailbox
Contents:
- ./PCB/ : kicad PCB files
- ./calibrate/ : calibration sketch to adjust the poti for letter distance
- ./letterbox_sensor/ : lora letterbox sensor sketch
- ./misc/ : payload decoder, sample http integration cgi
Compiled with platformio, hex flashed to attiny with ArduinoISP
Changes:
- created SMD PCB
- onboard 868MHz PCB antenna after TI document http://www.ti.com/lit/an/swra227e/swra227e.pdf
- switched MISO/MOSI lines of RFM95
- Attiny pin renumbering 0...10 -> 10...0
- sensor pin naming changed from 8 -> A2, otherwise no ADC reading
- added basic temperature reading from RFM95
- added sensor raw value, voltage, temperature in lora package
BOM (digikey.de):
| Part number | Description |
|---|---|
| ATTINY84A-SSUR | IC MCU 8BIT 14SOIC |
| HSDL-9100-021 | PROXIMITY SENSOR |
| RFM95W-868S2 | RF TXRX MODULE |
| 3314G-1-105E | TRIMMER 1M OHM |
| BU2032SM-FH-GTR | CR2032 COIN CELL HOLDER |
| HLE-103-02-L-DV | CONN RCPT 6POS |
| AA3528LSECKT/J4 | LED ORANGE |
| CRGCQ1206F33R | 33R 1206 |
| CRGCQ1206F220R | 220R 1206 |
| LQG18HN1N8S00D | IND 1.8NH 0603 |
| GRM1885C1H2R7CA01D | CAP 2.7PF 0603 |
An extended web ui by Peter is available here: https://github.com/pbiering/letterbox-sensor-web
Have fun!
Parts
14| Qty | Value | Footprint | References |
|---|---|---|---|
| 1 | 1M | Potentiometer_SMD:Potentiometer_Bourns_3314G_Vertical | R3 |
| 1 | 220 | Resistor_SMD:R_1206_3216Metric | R2 |
| 1 | 33 | Resistor_SMD:R_1206_3216Metric | R1 |
| 1 | ATtiny84-20PU | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | Attiny 84 |
| 1 | AVR-ISP-6 | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical_SMD | ISP |
| 1 | Antenna | Antennas:TI-DN024-SL-SHORT | AE1 |
| 1 | C_Small | Capacitor_SMD:C_0603_1608Metric_Pad1.05x0.95mm_HandSolder | C1 |
| 1 | Conn_01x02 | Battery:BatteryHolder_Keystone_1058_1x2032 | CR2032 |
| 1 | HSDL-9100-021 | Package_DIP:HSDL-9100 | D1 |
| 1 | L | Inductor_SMD:L_0603_1608Metric | L1 |
| 1 | LED | LED_SMD:LED_PLCC_2835_Handsoldering | D2 |
| 1 | LOGO | Logos:dragon3 | G*** |
| 1 | LOGO | Logos:LoRa | G*** |
| 1 | RFM95W | RF_Module:HOPERF_RFM9XW_SMD | U2 |
Questions
How big is the Briefkastensensor PCB?
It measures 116 × 40 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Briefkastensensor use?
14 parts, built around the ATTINY84-20PU, HSDL-9100-021 and RFM95W. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Briefkastensensor KiCad files?
From the hierle/letterbox-sensor repository on GitHub, at the commit this page was made from: the board is PCB/briefkastensensor.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Briefkastensensor design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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